1. Field of the Invention
The present invention relates generally to an improved method of weldbonding, and more particularly to a method of weldbonding photonic or electro-optical components, and to devices comprising such weldbonded components.
2. Technical Background
With rapidly increasing demand for photonic or opto-electronic devices (for example lasers or LED based portable or embedded projectors), one of the biggest challenges in assembling these devices is connecting or joining various components to one another to provide high optical coupling efficiency between these components, and maintaining the performance of the assembled device stable over time and during temperature variations.
Laser welding has been used in a variety of applications in the assembly of photonic components. During welding, the rapid solidification of the welded parts and the associated material shrinkage can lead to a relative movement between the pre-aligned components (process induced misalignment). This is also referred to as Post Weld Shift (PWS). The optical output power and/or optical coupling efficiency between welded photonic or opto-electronic components may be significantly reduced by PWS.
The use of combined adhesive bonding and welding has been considered previously for aero and auto applications. In these applications, large area metal sheets are glued and welded to provide structural/strength characteristics. This process is referred to as weldbonding. The adhesive is sandwiched between the metal sheets and the welding is performed subsequently through the sheets. The welding provides the benefits of instant strength and high peel resistance, whereas the adhesive bonding provides fatigue and vibration resistance and improved strength and durability. The focus is on large area bonding and structural requirements, not on high precision alignment, or optical coupling between components. Thus, to our knowledge, the weldbonding art does not address prevention of movement at the submicron level of the bonded parts during the welding process.